Insulin Resistance | T-IR- Study to Understand the Effects of Testosterone and Estrogen on the Body's Response to the Hormone Insulin

Insulin Resistance research study

What is the primary objective of this study?

The purpose of this research study is to understand the effects of testosterone and estrogen on the body's response to the hormone insulin.

Who is eligible to participate?

Inclusion Criteria: - Prostate-specific antigen (PSA) ≤ 3 ng/mL - Age 25-55 years - Ability to understand the study, study procedures and provide informed consent - Serum total T > 300 ng/dL - Normal reproductive history and exam - International Prostate Symptom Score (IPSS) < 11 Exclusion Criteria: - A history of prostate cancer including suspicious digital rectal exam (DRE) or history of highgrade prostatic intraepithelial neoplasia (PIN) on prostate biopsy - Invasive therapy for benign prostatic hyperplasia (BPH) in the past - History of acute urinary retention in the previous 3 months - Current or recent past use of androgenic or anti-androgenic drugs, steroids or drugs which interfere with steroid metabolism (within the last 3 months) - Current use of statins or glucocorticoids - Severe systemic illness (renal, liver, cardiac, lung disease, cancer, diabetes mellitus) or skin disease - A history of or current breast cancer - Known, untreated obstructive sleep apnea - Hematocrit > 50 or < 34 - Hypersensitivity to any of the drugs used in the study - History of a bleeding disorder or anticoagulation - Participation in any other drug study within past 90 days - History of drug or alcohol abuse within the last 12 months - Weight > 280 lbs. or BMI ≥ 33 - Desire for fertility in the next 6 months or current pregnant partner - Sperm concentration <14 million/ml - Significant, uncontrolled hypertension (BP >160/100 mmHg); subjects with well-controlled BP on medical therapy will be eligible to participate

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Insulin Resistance

Type 2 Diabetes Mellitus


Androgen Deficiency

Metabolic Disease

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:Acyline300 mcg/mL administered subcutaneously (at Day 0, Week 2)

Drug:Testosterone 1.62% gelTransdermal Testosterone Gel (either 1.25g or 5g/d) for 4 weeks

Drug:LetrozoleLetrozole oral aromatase inhibitor 5mg daily for 4 weeks

Drug:Placebo gel (for Testosterone 1.62% gel)placebo gel manufactured to mimic Testosterone 1.62% gel

Drug:Placebo pill (for Letrozole)Oral placebo aromatase inhibitor to mimic Letrozole 5mg/d

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Acyline (300mcg/kg) + placebo transdermal gel + placebo pill daily

Acyline (300mcg/kg) + Testosterone gel (1.25g) daily + placebo pill daily

Acyline (300mcg/kg) + Testosterone gel (5g) daily + placebo pill daily

Acyline (300mcg/kg) + Testosterone gel (5g) daily + letrozole (5mg) daily

Study Status


Start Date: June 2013

Completed Date: December 2017

Phase: Phase 1/Phase 2

Type: Interventional


Primary Outcome: Insulin Sensitivity Quantified by Matsuda Index

Secondary Outcome: Changes in Body Composition

Study sponsors, principal investigator, and references

Principal Investigator: William J Bremner, MD, PhD

Lead Sponsor: University of Washington


More information:

Flegal KM. Excess deaths associated with obesity: cause and effect. Int J Obes (Lond). 2006 Aug;30(8):1171-2.

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